public class Test {

	public static void main (String [] args){
	
		StringBuffer s = new StringBuffer ("xxxzzzyyy");
		s = s.delete(1,3);
		System.out.println(s);
		s = s.replace(1,3,"y");
		System.out.println(s);
		s = s.delete(3,6);
		System.out.println(s);
	}

}

